Diffraction experiments with crystals whose structures are known, and X-ray absorption spectra of the same materials, will be analyzed to measure the anomalous scattering properties of various elements in various chemical states at wavelengths near absorption edges. Special attention will be given to the effects of polarization which modify the absorption and scattering is some of these materials. The purpose is to gain a better understanding of X-ray dispersion and to seek better ways to use it to study chemical structure.